Yarn splicing device

ABSTRACT

A yarn splicing device ( 10 ) for pneumatically joining two yarn ends ( 31, 32 ), with a splicing head ( 19 ) that is fixed on a foundation ( 22 ) and comprises a splicing conduit ( 20 ) with at least one opening ( 34 ) for delivering compressed air. The splicing conduit ( 20 ) comprises at least two additional suction intake openings ( 33 ) that can be loaded with a vacuum and are arranged on both sides of the opening ( 34 ) for delivering compressed air.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of German patent application No. 101 50 578.7 filed Oct. 12, 2001, herein incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a yarn splicing device and, more particularly, to a yarn splicing device for pneumatically joining two yarn ends by means of a splicing head fixed on a foundation and a splicing conduit with at least one compressed air opening loadable in a defined manner for delivering compressed air into the splicing head.

[0003] Yarn splicing devices have long been known in conjunction with automatic cheese winders and have been described in detail in numerous protective right applications.

[0004] For example, German Patent Publication DE 39 35 536 C2 describes a pneumatic yarn splicing device comprising a splicing head with a splicing conduit having an almost circular cross section. Tangentially arranged openings for delivering compressed air empty tangentially into the splicing conduit, that has a through slot on its top for inserting the yarn ends to be spliced. The yarn insertion slot and therewith the splicing conduit are closed during the splicing process by a cover element.

[0005] The yarn ends to be spliced are prepared before the actual splicing process, that is, the yarn ends are at least partially freed of their yarn twist. The preparation of the yarn ends can take place either pneumatically via so-called yarn end opening tubes, as disclosed in German Patent Publication DE 39 35 536 C2, or mechanically by two friction disks working in opposite directions, as described, e.g., in German Patent Publication DE 30 29 452 C2.

[0006] The known yarn splicing devices have proven themselves in practice in principle; however, they reveal weaknesses if fine and extremely fine yarns are to be spliced.

SUMMARY OF THE INVENTION

[0007] In view the state of the art cited above, it is accordingly a general object of the present invention to create a yarn splicing device that makes it possible to join even problematic yarns, especially fine and extremely fine yarns, in a reliable manner.

[0008] The invention addresses this objective by providing a yarn splicing device for pneumatically joining two yarn ends, comprising a splicing head fixed on a foundation and having a splicing conduit with at least one first compressed air opening loadable in a defined manner for delivering compressed air into the splicing head and at least two suction intake openings loadable with a vacuum, the suction intake openings being arranged respectively on opposite sides of the compressed air opening.

[0009] This design, in accordance with the present invention, of a splicing head with at least one compressed air opening, preferably arranged centrally in the splicing conduit, and with at least two adjacent vacuum-loadable suction intake openings, has the particular advantage that the fibers lying parallel to a very large extent after the preparation of the yarn ends remain reliably fixed in the splicing conduit even during the actual splicing procedure. That is, a collection of material in the area of the connection openings can be achieved by means of the pneumatic fixing of the fibers in the splicing conduit which collection makes it possible to produce durable splices even in the case of fine and extremely fine yarns. Moreover, such vacuum-loaded suction intake openings, make possible a retention or storing of the neutralized yarn twist until the actual splicing procedure, especially in the case of mechanically prepared yarn ends, that is, in the case of yarn ends that were untwisted between two friction disks working in opposite directions. This stored yarn twist can be released after the splicing process is completed and then imparts further strength to the yarn joining site.

[0010] In particular, a symmetrical arrangement of the vacuum-loadable suction intake openings assures that the yarn ends are held inside the splicing conduit in a state that is tensioned to a very large extent, which has a positive effect on the appearance and on the durability of the yarn connection.

[0011] A preferred embodiment provides that the individual suction intake openings are connected via a common pneumatic line to a vacuum source. Such a design assures not only a uniform loading of the yarn ends to be spliced but also constitutes a method of constructing the splicing head that is advantageous due to its simplicity.

[0012] An advantageous embodiment provides that the suction intake openings are connected to a separate vacuum source. Such a pneumatic decoupling of the splicing device of the invention from the regular vacuum system of the textile machine can assure a largely uniform quality of the spliced connections since variations in pressure such as are almost unavoidable in the vacuum system of a textile machine will not have an effect on the yarn splicing device.

[0013] The separate vacuum source is designed, e.g., as an injector nozzle. The use of such an injector nozzle is an economical possibility of realizing a reliable, additional vacuum producer in a simple manner.

[0014] According to another aspect of the invention, the vacuum-loadable suction intake openings advantageously empty in a bottom area of the splicing conduit. The bottom area of the splicing conduit has a U-shaped or V-shaped cross section in a preferred embodiment. Such an advantageous shape of the bottom of the splicing conduit favors the parallel alignment of the fibers of the yarn ends to be spliced and therefore results in a uniform connection of material at the bottom of the splicing conduit.

[0015] The invention is further explained in the following specification with reference to an exemplary embodiment shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a lateral view of a work station of an automatic cheese winder with a yarn splicing device in accordance with the present invention.

[0017]FIG. 2 is a perspective view of a yarn splicing device in accordance with the present invention, with a pneumatically loadable splicing head as well as pneumatically operating tubes for preparing yarn ends.

[0018]FIG. 3 is a front view of the yarn splicing device in accordance with the present invention with a splicing head that can be loaded with a vacuum and with mechanical friction disks for preparing the yarn ends.

[0019]FIG. 4 is a lateral view of the yarn splicing device in accordance with FIG. 3.

[0020]FIG. 5 is a perspective view of the pneumatically loadable splicing head of a yarn splicing device in accordance with the present invention on a larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0021]FIG. 1 schematically shows a front view of a textile machine, which in this exemplary embodiment is an automatic cheese winder for producing yarn cheeses identified in its totality by reference numeral 1. Such automatic cheese winders usually comprise a plurality of similar work stations, in the present instance winding heads 2, between their end frames (not shown). Spinning cops 9 produced, e.g., on a ring spinning machine are rewound to large-volume cheeses 15 on these winding heads 2, as is known and therefore not explained in detail. After their completion, these cheeses 15 are transferred by an automatically operating service unit, preferably a cheese changer (not shown), onto cheese transport device 21 running the length of the machine and are transported to a cheese unloading station or the like arranged at one end of the machine.

[0022] Usually, such automatic cheese winders 1 also comprise a logistics device in the form of a bobbin and tube transport system 3 in which spinning cops 9 or empty yarn tubes circulate in vertical alignment on transport plates 8. Of this bobbin and tube transport system 3, FIG. 1 shows only cop supply extent 4, reversibly drivable storage extent 5, one of transverse transport extent 6 leading to winding heads 2 and tube return extent 7.

[0023] Moreover, such automatic cheese winders 1 comprise as a rule a central control unit (not shown) connected via a machine bus to separate work-station computers 29 of individual winding heads 2 and to a control device of the service unit.

[0024] Supplied spinning cops 9 are rewound to large-volume cheeses 15 in unwinding positions AS located in the area of transverse transport extents 6 on winding heads 2. To this end the individual winding heads comprise, as is known and therefore only schematically indicated, various devices that assure an orderly operation of these work stations. These devices comprise, e.g., suction nozzle 12, grasper tube 25 and yarn joining device 10. Yarn joining device 10 is preferably designed as a pneumatic splicer.

[0025] As is indicated in FIG. 1, pneumatic yarn splicing device 10 is set back somewhat relative to the regular course of yarn travel and comprises, e.g., as indicated in FIG. 2, upper yarn clamping and cutting device 11 and lower yarn clamping and cutting device 17.

[0026] Such winding heads 2 also comprise other devices (not shown in detail) such as a yarn tensioner, a yarn cleaner, a paraffining device, a yarn cutting device, a force sensor for yarn traction and a bottom yarn sensor.

[0027] The winding of cheeses 15 takes place on respective winding devices 24 associated with each winding head. Such winding devices 24 comprise, among other things, a creel 28 supported in such a manner that it can move about the axis of pivot shaft 13 and comprises a device for rotatably holding a cheese tube. During the winding process, the cheese 15 is supported in a freely rotatable manner in creel 28 while resting with its circumferential surface on grooved drum 14 to be friction driven thereby.

[0028] As has already been indicated above, each winding head 2 comprises a suction nozzle 12 and a grasper tube 25. Suction nozzle 12 is supported in such a manner that it can rotate in a limited fashion about pivot axis 16 and grasper tube 25 is supported in such a manner that it can rotate in a limited fashion about pivot axis 26.

[0029]FIG. 2 shows a perspective view of yarn joining device 10, with suction nozzle 12 shown standing in a yarn insertion position and grasper tube 25 similarly arranged in a corresponding yarn insertion position. Suction nozzle 12 has retrieved upper yarn end 31 from cheese 15 and inserted it into splicing conduit 20 of splicing head 19. Moreover, bottom yarn end 32, that is connected to spinning cop 9 and is fixed as a rule after a yarn break in a yarn tensioner (not shown), is retrieved by grasper tube 25 and also inserted into splicing conduit 20.

[0030] As is indicated in FIG. 2, splicing head 19 is connected, e.g., via screw connection 27 to foundation 22 that comprises several pneumatic connections and into which pneumatically loadable yarn end preparation tubes 18, among other things, are formed. The yarn clamping and cutting devices 11, 17 are arranged above and below foundation 22 of yarn splicing device 10. As can be seen, upper yarn end 31 rests in cutting element 17″ of yarn clamping and cutting device 17 arranged below splicing head 19 and rests in clamping element 11′ of upper yarn clamping and cutting device 11 arranged above splicing head 19. Bottom yarn 32 is correspondingly held in clamping element 17′ of lower yarn clamping and cutting device 17 and crosses cutting element 11″ of upper yarn clamping and cutting device 11.

[0031]FIG. 3 shows a front view of another embodiment of yarn splicing device 10. Yarn splicing device 10 is arranged between two mechanically operating friction rings 42, 43 that can be driven in opposing directions. Friction ring 42, which is more forwardly disposed according to FIG. 3, can rotate, e.g., counterclockwise in a limited fashion and rear friction ring 43 can rotate clockwise in a limited fashion.

[0032] As is also apparent from FIG. 3, splicing conduit 20 of splicing head 19 comprises at least one opening for delivering compressed air 34 and at least two suction intake openings 33. Compressed air opening 34 communicates with compressed-air source 36 via pneumatic line 35 into which distributing valve 37 is connected. Suction intake openings 33 are connected via line 39 comprising distributing valve 40 to vacuum source 41. Distributing valve 37 and distributing valve 40 can be controlled by workstation computer 29 via control lead 38.

[0033]FIG. 4 shows previously described yarn splicing device 10 in a side view.

[0034]FIG. 5 shows the constructive design of splicing head 19 in accordance with the invention in more detail. Splicing head 19 is preferably fixed via screw connection to a foundation 22 of yarn splicing device 10, as already indicated above, and defines a splicing conduit 20 open at the top.

[0035] Splicing conduit 20 can be closed by cover element 23 shown in dotted lines, and is configured in the bottom area 30 of the conduit 20 in a U-shaped cross section in the exemplary embodiment. In addition to at least one opening for delivering compressed air 34 typically arranged midway along the conduit 20, other suction intake openings 33 are preferably arranged symmetrically relative to compressed air opening 34 to empty into conduit bottom area 30. These suction intake openings 33 are connected, as already indicated above, via vacuum line 39 to vacuum source 41.

[0036] The operation of the splicing device may thus be understood. If a winding interruption has occurred on one of winding heads 2 of automatic cheese winder 1, e.g., due to a regular cleaner cut of a yarn break, suction nozzle 12 takes upper yarn end 31 that wound up on cheese 15 and brings it to yarn splicing device 10. That is, upper yarn end 31 taken up by suction nozzle 12 is threaded into splicing conduit 20 of splicing head 19 of yarn splicing device 10, into clamping element 11′ of the upper and into cutting element 17″ of lower yarn cutting and clamping device 11 and 17 (see FIG. 2).

[0037] At the same time or subsequently, bottom yarn end 32 held in the yarn tensioner is retrieved by grasper tube 25. To this end, grasper tube 25 pivots initially into the area of the yarn tensioner and sucks in bottom yarn end 32 thereat, as it is released at the same time by the yarn tensioner. Grasper tube 25 subsequently pivots into the upper work position indicated in FIGS. 2, 3. During this pivoting movement bottom yarn end 32 is likewise placed into splicing conduit 20 of splicing head 19, as shown by way of example in FIGS. 2, 3. Moreover, bottom yarn end 32 then rests in clamping element 17′ of the lower yarn cutting and clamping device 17 and in cutting element 11″ of the upper yarn cutting and clamping device 11.

[0038] After splicing head 19 has been closed with cover element 23, the yarn ends 31, 32 fixed in yarn cutting and clamping devices 11 and 17 are cut and the severed portion of bottom yarn end 32 is removed by grasper tube 25 and the severed portion of upper yarn end 31 is removed by suction nozzle 12.

[0039] At the same time, the upper yarn end 31 and bottom yarn end 32 extending out of splicing conduit 20 are drawn by suction into one of vacuum-loaded yarn-end preparation tubes 18, where they are at least partially untwisted counter to their original yarn twist, preferably pneumatically.

[0040] The end portions of upper and lower yarn ends 31, 32 prepared in this manner are subsequently drawn by a so-called loop puller (not shown) or the like into splicing conduit 20 and into the bottom area 30 that is, e.g., U-shaped or V-shaped in cross section. That is, the upper and lower yarn ends 31, 32 slide into bottom area 30 of splicing conduit 20, where they are pneumatically fixed after distributing valve 40 has been opened via suction intake openings 33, that are then loaded with a vacuum. The individual fibers of the bottom yarn end 31 and of upper yarn end 32, that are arranged at first almost in parallel in bottom 30 of splicing conduit 20, are subsequently intermingled with each other by a jet of splicing air that exits out of compressed air opening 34 and is initiated by opening distributing valve 37. That is, the two yarn ends of bottom yarn 32 and of upper yarn 31 are pneumatically spliced.

[0041] The invention is not limited to the exemplary embodiments shown. For example, several openings 34 for delivering compressed air can empty into conduit bottom area 30 and can be arranged both radially as well as also tangentially. Even the arrangement or number of vacuum-loadable suction intake openings 33 can vary without departing from the general inventive concept.

[0042] It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. 

What is claimed is:
 1. A yarn splicing device for pneumatically joining two yarn ends, comprising a splicing head fixed on a foundation and having a splicing conduit with at least one first compressed air opening loadable in a defined manner for delivering compressed air into the splicing head and at least two suction intake openings loadable with a vacuum, the suction intake openings being arranged respectively on opposite sides of the compressed air opening.
 2. The yarn splicing device according to claim 1, characterized in that the suction intake openings are arranged symmetrically to the compressed air opening.
 3. The yarn splicing device according to claim 1, characterized in that the suction intake openings are connected via a common vacuum line to a vacuum source.
 4. The yarn splicing device according to claim 3, further comprising a second independent vacuum source.
 5. The yarn splicing device according to claim 4, characterized in that the second independent vacuum source comprises an injector nozzle.
 6. The yarn splicing device according to claim 1, characterized in that the suction intake openings empty in a bottom area of the splicing conduit.
 7. The yarn splicing device according to claim 6, characterized in that the bottom area of the splicing conduit has an essentially U-shaped cross section.
 8. The yarn splicing device according to claim 6, characterized in that the bottom area of the splicing conduit has an essentially V-shaped cross section. 